C-shaped Canal Research Articles

Evaluation of C-shaped canals in mandibular second molars of a selected patient group using cone beam computed tomography: prevalence, configuration and radicular groove types.

The aim of the present study was to examine the prevalence, symmetry and configurations of C-shaped canals and radicular groove types in mandibular second molars according to age and sex in a Turkish sub-population using cone beam computed tomography (CBCT). In total, 674 CBCT images (368 females and 306 males, aged 18-76 years) of 1348 mandibular second molars were evaluated. The symmetry, configuration of C-shaped root canals, radicular groove types with age and sex were noted. One sample chi-square test and chi-square test were used to determine statistically significant differences. The statistical significance level was set at p < 0.05. Of the 1348 mandibular second molars evaluated, 10.7% had C-shaped root canals. C-shaped root canals appeared to be significantly more common in females than in males (p < 0.05). C1 (44.4%) was the most frequent configuration in the coronal third, and C2 (44.4%), and C4 (31.9%) were the most frequent configurations in middle and apical thirds, respectively. Type 2 (45.1%) was the most common radicular groove type (p < 0.05). The frequency of C-shaped root canals in mandibular second molars in a Turkish sub-population was considerably high (10.7%). CBCT can aid the detection of C-shaped canals and their configurations. Dentists should consider the possibility of C-shaped canals in root canal treatment of mandibular second molars, as these configurations have implications for biomechanical preparation and filling methods.

C-SHAPED CANALS IN MANDIBULAR SECOND MOLARS: A CASE SERIES

The mandibular molars are more prone to aberrations of canals. They include bifurcation and trifurcation of canals, fusion of roots, extreme canal curvatures and c-shaped canals which makes it difcult to diagnose and manage. The failure to treat them leads to re-infection and persistence of infection in the tooth. Hence, it is of utmost importance for the clinician to know the morphologic variations. The present case series aims to give a clinical insight of such aberrations. The ten cases presents with mandibular second molar with “c” shaped root canal system, which was diagnosed with Radiovisiography. The cases were treated endodontically and successfully managed

Prevalence and Morphology of C-Shaped Canals: A CBCT Analysis in a Korean Population.

This retrospective study of roots with C-shaped canals investigated their prevalence, configuration type, and lingual wall thickness, as well as the panoramic radiographic features of roots in permanent mandibular second molars confirmed to have C-shaped canals on cone-beam computed tomography (CBCT) in a Korean population. In total, 1884 CBCT images of mandibular second molars were examined by two endodontists to analyze the presence of C-shaped canals according to age and sex. The bilateral occurrence of C-shaped roots and their morphology on panoramic radiography were assessed and statistically analyzed using the chi-square test. The classification of Fan et al. was applied to categorize the configurations of C-shaped canals. The lingual wall thickness was calculated in the mesial, middle, and distal areas at the orifice and at 5 mm from the apex. The Mann–Whitney U test was used to analyze the mean difference of lingual wall thickness between the apex and orifice level. A P value of 0.05 was considered to indicate statistical significance in the statistical analyses. Of 2508 mandibular second molars, 924 (36.8%) had C-shaped root canals. The prevalence was significantly lower in the over 61 age group (24.08%) than in the 21–30-year age group (40.02%) and was higher in women (42.32%). Most cases were bilateral (85.9%). The C1 type was the most common (35.3%). The prevalence of C1 type canals decreased, while that of C3b type canals increased with age. In 75.2% of teeth having C-shaped root canals on CBCT, fused roots were observed on panoramic views. The difference in the lingual wall thickness at the orifice and 5 mm from the apex was significant in the middle area in all configurations of C-shaped root canals. When performing nonsurgical or surgical endodontic procedures of the mandibular second molars, clinicians should consider age, sex, ethnicity, and anatomical variations.

In Mandibular Second Molars, Prevalence of C-Shaped Root Canals

Objective: The purpose of this study was to perform cone beam computed tomography (CBCT) to assess the frequency of mandibular second molars with C-shaped root canals in a population living in Pakistan. Study Design: Retrospective study Place and Duration: This retrospective study was conducted at Bakhtawar Amin Medical and Dental College during in the period from June, 2022 to November, 2022. Methods: Total 118 patients were presented with mandibular second molars scheduled for root canal treatment. CBCT scans of patients from diagnostic imaging center were selected. C-shaped root canals were determined by radiographic method using Fan’s criteria. The frequency and distribution of canals and their configuration along with the position of lingual/buccal grooves in the images were evaluated. SPSS 22.0 was used to analyze all data. Results: There were majority 72 (61.02%) females and 46 (38.98%) were males in this study. In our study mean age of the patients was 26.16±13.74 years. Frequency of C-shaped mandibular second molars was found in 12 (10.2%) cases. Among 12 cases, majority of the C-shaped root canals found in right side 7 (5.9%) and 5 (4.2%) C-shaped root canals found in left side. Majority of the C-shaped root canals found in females. Frequency of buccal groove among C-shaped root canals was 6 followed by both buccal and lingual groove in 4 and only lingual groove in 2 cases. Conclusion: According to CBCT analysis, 10.2% of second molars exhibited C-shaped canals. These teeth stood out due to the presence of a deep buccal groove. Right-sided mandibular second molar presence was statistically significant (P = 0.016), according to the data. Keywords: CBCT, Mandibular Second Molars, C-shaped canals, Buccal Groove

Micro-computed tomographic evaluation of root canal morphology in mandibular first premolars from a Colombian population.

Dental anatomy can vary significantly between different populations from different countries. Dental anatomical variations are of great interest to the dental professional, especially to endodontists, since they can influence the outcome of endodontic treatment. The purpose of the present study was to describe the anatomical variations of the root canal in mandibular first premolars in a population from Colombia, using micro-computed tomography. Fifty mandibular first premolars were scanned on a SkyScan 1174 and the microcomputed tomographic images were reconstructed. Anatomy was assessed using three-dimensional models. The parameters used were: Vertucci's classification, area and volume, perimeter, circularity, and major and minor diameter at 1, 2 and 3 mm from the apical foramen. According to the Vertucci's classification, teeth were classified as: types I (40%), V (24%), VII (4%) and III (4%), with 28% not classifiable. C-shaped canals were found in 1.8% of the sample. Mean evaluations at 1, 2, 3 mm of the foramen were as follows, respectively: perimeter 1.07 ± 0.57, 1.27 ± 0.78 and 1.57 ± 0.84 mm; circularity 0.59 ± 0.19, 0.57 ± 0.20 and 0.56 ± 0.22; maximum diameter 0.41 ± 0.23, 0.48 ± 0.33 and 0.60 ± 0.37 mm; minimum diameter 0.24 ± 0.10, 0.26 0.11 and 0.21 ± 0.13 mm. Mean total area and volume were 61.27 ± 16.47 mm2 and 12.47 ± 4.95 mm3, respectively. There was wide anatomical variation in mandibular first premolars from Colombian individuals, reinforcing the need for proper anatomical knowledge to establish more effective strategies for endodontic treatment.

Root dentine thickness in C-shaped lower second molars after instrumentation: A CBCT and micro-CT study.

Stripping perforation is a possible complication in instrumentation of C-shaped canals. This study evaluated the minimum thickness of the root canal wall in C-shaped teeth after instrumentation. Twelve extracted C-shaped mandibular second molars (four teeth of type I, II and III each) were examined by CBCT (voxel size 90μm) before and after instrumentation with WOG primary file. Micro-CT scans (voxel size 30μm) were obtained after instrumentation. Percentage of canal wall area touched by the file and minimum thickness of dentine were measured and compared between CBCT and micro-CT. In type I C-shape canals, less than 10% of the canal wall area was touched by the instrument. In ten teeth, the shortest distance to root surface was from the instrumented area; no perforations occurred. CBCT and micro-CT measurements were in good agreement in ten cases; in two teeth, micro-CT revealed considerably shorter distance to root surface. The two shortest distances were 0.27 and 0.41mm.

Efficacy of root canal treatment in c-shaped canals with adjunctive photodynamic therapy using micro-CT.

To investigate the efficacy of conventional root canal treatment (cRCT) with adjunctive photodynamic therapy (aPDT) against microbial biofilms within infected c-shaped root canals. In this in vitro report, the inoculation of 20 freshly extracted human mandibular molar teeth having c-shaped root canal configuration was performed with E. faecalis and P. aeruginosa to produce three-day biofilms in prepared canal system. PDT used a combination of chlorin (ce6) and polyethylenimine (PEI) as the photosensitizer (PS). A 200 μ-fiber was employed to deliver a 660 nm diode laser light into the root canal, and this was compared and conjugated with conventional endodontic treatment utilizing antiseptic irrigation and mechanical debridement. The utilization of aPDT (group-2) resulted in a considerable decrease in the count of E. faecalis and P. aeruginosa from 12.84 ± 2.18 CFU/mL to 5.13 ± 0.67 CFU/mL, and from 14.06 ± 3.98 CFU/mL to 4.82 ± 1.05 CFU/mL pre-and post-treatment, respectively. A statistically significant reduction in the bacterial counts of both microbes was observed after treatment among the samples of the both study groups (p < 0.05). Specimens in group-2 (8.42 ± 1.14 MPa) demonstrated the highest mean push-out bond strength, whereas the lowest was shown by samples in group-1 (7.08 ± 1.09 MPa). ANOVA showed no statistical difference between the research groups (p = 0.676). The independent t-test revealed that the mean push-out bond strength scores of the cervical segments were higher than the apical and middle segments of roots in research groups (p < 0.05). In c-shaped root canals, the application of photodynamic therapy as an adjuvant to conventional root canal treatment contributes to a statistically significant decrease in the microbial count of E. faecalis and P. aeruginosa along with an improved push-out bond strength of the root canal filling material with root.

MANAGEMENT OF C-SHAPED CANAL IN MANDIBULAR SECOND MOLAR: A CASE REPORT

Variations of root canal systems need not always be in the form of extra canals. Clinicians should be aware that there is a possibility of existence of fewer numbers of roots and root canals than normal, which presents varied canal anatomy and poses a challenge to the clinician's expertise. This case report deals with the management of an unusual case of C-shaped canal in mandibular second molar. Cone-beam computed tomography (CBCT) was employed to conrm the extension of the unusual anatomy. 3-D Obturation done with the help of thermoplastic obturation unit.

C-Shaped canal system in mandibular premolars evaluated by cone-beam computed tomography in a population of the Autonomous City of Buenos Aires, Argentina

ObjectiveTo evaluate cone-beam computed tomography images in an Argentine population in order to determine the presence of mandibular premolars with C-shaped canal system and classify them. Methods697 images were observed, 170 of them fulfilling the selection criteria. Once established the presence of a C-shaped canal system, premolars were classified using Fan’s criteria. Data description was made by frequencies and percentages rates, with a 95% confidence interval according to the score method. Comparisons were assessed by means of the Chi-square test with a significance level equal to 5%. ResultsOf 269 first premolars, 27 teeth showed C-shaped canal system, i.e. 10%, and of 231 second premolars, 4 presented C-shaped canal system, i.e. 2%. Out of 17 patients presenting first premolars in both sides, 6 showed a bilateral C-shaped canal system pattern and 11 did not present this condition. When the condition was unilateral (n = 15), 7 patients showed C-shaped canal in the tooth 3.4 and 8 patients showed C-shaped canal in the tooth 4.4. The second premolars showed C-shaped canals unilaterally. Along the canal, configuration variations at the three-thirds have been observed for the first and second mandibular premolars. ConclusionThe C-shaped canal system pattern prevalence in mandibular first and second premolars was estimated for the first time in an Argentine population, in vivo. The present report contributes to the epidemiological understanding of the anatomical variable of the inner dental configuration and its extrapolation to the clinical practice.

Deep-learning for predicting C-shaped canals in mandibular second molars on panoramic radiographs.

The aim of this study was to evaluate the use of a convolutional neural network (CNN) system for predicting C-shaped canals in mandibular second molars on panoramic radiographs. Panoramic and cone beam CT (CBCT) images obtained from June 2018 to May 2020 were screened and 1020 patients were selected. Our dataset of 2040 sound mandibular second molars comprised 887 C-shaped canals and 1153 non-C-shaped canals. To confirm the presence of a C-shaped canal, CBCT images were analyzed by a radiologist and set as the gold standard. A CNN-based deep-learning model for predicting C-shaped canals was built using Xception. The training and test sets were set to 80 to 20%, respectively. Diagnostic performance was evaluated using accuracy, sensitivity, specificity, and precision. Receiver-operating characteristics (ROC) curves were drawn, and the area under the curve (AUC) values were calculated. Further, gradient-weighted class activation maps (Grad-CAM) were generated to localize the anatomy that contributed to the predictions. The accuracy, sensitivity, specificity, and precision of the CNN model were 95.1, 92.7, 97.0, and 95.9%, respectively. Grad-CAM analysis showed that the CNN model mainly identified root canal shapes converging into the apex to predict the C-shaped canals, while the root furcation was predominantly used for predicting the non-C-shaped canals. The deep-learning system had significant accuracy in predicting C-shaped canals of mandibular second molars on panoramic radiographs.

Prevalence of C-shaped second mandibular molar canals in the population of central Serbia: A cone-beam computed tomography study

Background/Aim. C-shaped canals are a complex morphological variation of the tooth root canal system that, if present, could greatly affect the outcome of endodontic therapy. The prevalence of these canal configurations varies between the populations of different ethnic and geographical origins. Therefore, the goal of this study was to analyze the prevalence and morphology of mandibular second molar C-shaped canals in the population of Central Serbia. Methods. The study included a total of 1 99 mandibular second molars receiving a cone-beam computed tomography (CBCT) examination and determining the presence of C-shaped canal systems, their configuration, minimal wall thickness and its relative position on axial cross-sections at the coronal, middle, and apical level. Results. The prevalence of C-shaped mandibular second molars was 5.53%. C1 canal configuration was the most frequent at the coronal cross-section, while C2 configuration was the most frequent at middle and apical cross-sections. Minimal wall thickness decreased going apically, with the mean value of 1.01 mm at the coronal, 0.87 mm at the middle, and 0 .67 mm at the apical cross-sections. Minimal wall thickness was mostly directed lingually at all cross-sectional levels. Conclusion. C-shaped canals should be expected in mandibular second molars of the population of Central Serbia. CBCT was shown to be the most valuable technique to determine C-shaped canals and facilitate understanding of the C-shaped canal morphology; its implementation could improve the success of endodontic therapy, especially if the complex root canal configuration is present.

Mandibular second molars' C-shaped canal frequency in the Pakistani subpopulation: A retrospective cone-beam computed tomography clinical study

Introduction: The adequate knowledge of the canal configuration can improve the quality and prognosis of endodontic treatment. The aim of the study was to determine the frequency of C-shaped root canal in the mandibular permanent second molars among a Pakistani subpopulation sample by utilizing cone-beam computed tomography images. Materials and Methods: Cone-beam computed tomographic images of 360 patients with 720 mandibular second molars were analyzed for the presence of C-shaped canal configuration. The root canal system was classified according to Fan's classification at three distinct levels. Unilateral or bilateral presence of C-shaped root canals and the location of the longitudinal groove were assessed. Moreover, the correlation of frequency of C-shaped canal with the gender was measured using the Chi-square test. The data were analyzed using SPSS version 23. Results: Of 720 mandibular second molars of 360 patients, 10% of teeth were found to have C-shaped canals in 48 patients. The most commonly noted C-shaped canal configurations in the coronal and middle third were C1 (41.7%) and C3 (37.5%), respectively, whereas C2 (33.3%) and C4 (33.3%) configurations were commonly found in the apical third. Twenty-four of 48 patients had bilateral C-shaped root canals. Overall, 37.5% of the teeth were right-sided teeth and 62.5% were left-sided teeth. The frequency of C-shaped canals was significantly higher in females as compared to males, 15.6% and 4.2%, respectively (P = 0.03). The longitudinal groove was most commonly located on the lingual surface (66.7%). Conclusions: The frequency of C-shaped canal configuration in the Pakistani subpopulation was 10% in the mandibular second molar teeth.

Endodontic treatment of a hypertaurodont mandibular second molar with C-shaped canal: A case report

Taurodontism is a variation in tooth anatomy characterized by an enlarged pulp chamber with hypertaurodont being its most severe presentation. The complexity of endodontic treatment of hypertaurodont tooth may be compounded by coexistent C-shaped canal anatomy. A 26-year-old patient reported with spontaneous and lingering pain due to a deep carious lesion in the right mandibular second molar. Clinical and radiographic examinations were done. A diagnosis of symptomatic irreversible pulpitis with symptomatic apical periodontitis in a hypertaurodont with an associated C-shaped canal configuration was made. The cone-beam computed tomography image guide together with microscopic magnification was utilized to negotiate, clean, and shape the root canal system. The isthmus of the C-shaped canal was prepared with ultrasonic tips, while Endoactivator sonic irrigant activation was employed for effectively disinfecting of the uninstrumentable intercommunications, apical splits, and ramifications. The apical root canals were obturated by lateral condensation technique, while warm vertical compaction of gutta-percha was utilized to fill the remaining pulp chamber. A 1 year follow-up of the case reveals a functional tooth with no signs of periapical infection, indicating a successful treatment outcome.

Prevalence of C-shaped Canals and Three-rooted Mandibular Molars Using CBCT in a Selected Thai Population.

C-shaped canals and three rooted mandibular molars are challenging to treat. These anatomies are commonly found in mandibular molars, especially in the Mongoloid population. However, there is no report on these anatomies using cone-beam computed tomography on all three mandibular molars in Thais. The objectives of this study were to determine the prevalence of C-shaped canals and three-rooted mandibular molars in Thais and investigate whether there is a relationship between these morphology and gender. Three pre-calibrated observers independently determined the presence of each anatomy using a specific protocol in 753 molars from cone-beam computed tomographic images. The three observers randomly re-evaluated 20% of the samples to determine inter- and intra-observer agreement using Cohen's Kappa statistic. The relationship of these root canal anatomy with sex was analysed by the Chi-square test. The prevalence of C-shaped canals and three-rooted molars was 0.39% and 12.1%, 42.4% and 3.9%, and 16.6% and 9.1% in first, second, and third mandibular molars respectively. The inter-/intra-observer reliability of the results was extremely high. This cross-sectional study showed the prevalence of C-shaped canals in mandibular second molars was relatively high and should be considered normal root canal anatomy in Thais. The prevalence of three-rooted molars was highest in first molars and frequently found in third molars. Cone-beam computed tomography was a reliable technique to determine root canal anatomy.

Prevalence of middle mesial canals and Isthmi in mandibular molars in a subpopulation of Andhra Pradesh: an in vivo investigation using CBCT

Background: Pulp and root canal space is enigmatic and highly complex. Encountering rare has become a norm with the advancements in the technology of materials and types of equipment. The success of the root canal treatment depends on the effective removal of bacteria from the whole pulp space. A high percentage of the missed canal is reported for the failure of Endodontic therapy. Mandibular molars have complex root canal anatomy. Two roots with two canals in mesial root and one to two canals in distal root is a common occurrence. Nevertheless, the incidence of variation is relatively high, including separate distolingual, mesiobuccal, C-Shaped canals, isthmus, and additional canal in the mesial root. A wide range of the middle mesial canal occurrence, i.e., 3.1 to 46.1%, is reported in the world and 28.3% in North India. Aim: To identify the prevalence of the true middle mesial canal (MM) and configuration of Isthmi in the mesial root of the mandibular molar in the AP subpopulation of South India. Materials and methods: CBCT of 89 patients were randomly selected from the institutional database. Data entry was performed in Excel, and data analysis was done with the Statistical Package for Social Sciences (SPSS). Results: Four images (4.5%) revealed Middle Mesial canals with no statically significant occurrence. The frequency of isthmi in the mesial roots was 52.7%. This showed a considerable presence. Conclusion: MM canals are 4.5% in a subpopulation of Andhra Pradesh. Isthmuses are very common in the mesial roots of permanent mandibular molars. Isthmus about 58% was seen with Type II configuration that is the presence of two canals without a definite communication.

Endodontic management of a mandibular second molar with C-shaped canals

The aim of this case report is to explain the etiology and management of C-shaped canals. An important anatomic variant in root canal morphology, the C configuration, presents as a thin fin connecting the canals with a predilection for mandibular second molars. Early recognition of the C-shape becomes imperative for its successful management. Newer diagnostic tools have facilitated a more precise diagnosis of this condition. Clinical and radiographic diagnoses can aid in the identification and negotiation of the fan-shaped areas. The inaccessible areas and unique canal patterns make provision of optimum treatment quality a highly challenging proposition. Successful endodontic therapy of this canal configuration can be achieved with rotary and hand instrumentation assisted with ultrasonics.

Endodontic management of a mandibular premolar with a concurrent occurrence of dental anomalies

Developmentally abnormal teeth presenting a complex root canal morphology requires special endodontic management. The present case report demonstrates successful endodontic management of a mandibular first premolar with an unusual concurrent occurrence of a double tooth and dens evaginatus with a C-shaped canal configuration in a 21-year-old patient that was diagnosed with pulpal necrosis with symptomatic apical periodontitis. In this case, the use of cone-beam computed tomography and the dental operating microscope contributed remarkably to the diagnosis and treatment of the complex root canal morphology of the anomalous tooth. Therefore, the use of recent advances in endodontics is strongly recommended in such cases to ensure predictable and successful results.

Disinfecting and Shaping Type I C-shaped Root Canals: A Correlative Micro–computed Tomographic and Molecular Microbiology Study

IntroductionThis ex vivo study compared the disinfection and shaping abilities of 2 preparation protocols in C-shaped canals. MethodsMandibular second molars with type I C-shaped canals were pair matched based on micro–computed tomographic (micro-CT) analysis and distributed into 2 groups. The canals were contaminated with a mixed bacterial culture and prepared using 2 protocols, both with 2.5% sodium hypochlorite irrigation: XP-endo Shaper (FKG Dentaire, La Chaux-de-Fonds, Switzerland) supplemented with XP-endo Finisher (FKG Dentaire) (XP-E) and BioRaCe (FKG Dentaire) supplemented with a Hedström file (Dentsply/Sirona, Tulsa, OK) (BR-Hed). Micro-CT scans and intracanal bacteriologic samples were taken before (scan #1 and sample 1) and after preparation (scan #2 and sample 2) and after the supplementary step (scan #3 and sample 3). Canal shaping was evaluated by micro-CT imaging, and disinfection was assessed by quantitative polymerase chain reaction. ResultsMicro-CT data from the XP-E (n = 21) and BR-Hed (n = 23) protocols revealed no significant differences between groups regarding shaping parameters (canal volume, surface area, structure model index, and prepared walls) after preparation and after the supplementary step (P > .05). All these parameters significantly increased after each preparation step (P < .05), except for structure model index changes after the XP-endo Finisher (P > .05). Bacteriologic data from the XP-E (n = 21) and BR-Hed (n = 22) groups showed that 14 (66.7%) and 10 (45.5%) S2 samples still had detectable bacteria, respectively. The corresponding figures for supplementary steps with the XP-endo Finisher and Hedström file were 11 (52.4%) and 10 (45.5%), respectively. Bacterial counts in sample 1 significantly decreased in samples 2 and 3 in both groups (P < .01). Intragroup comparison between sample 2 and sample 3 showed a 66% reduction in counts after using the Hedström file and 18% after using the XP-endo Finisher (P > .05 for both groups). The quantitative bacterial reduction was not different between groups (P > .05). ConclusionsThe XP-endo Shaper and BioRaCe systems have similar disinfecting and shaping abilities in C-shaped canals. Supplementary steps with the Hedström file and the XP-endo Finisher were similarly effective in improving shaping, but this was not sufficient to enhance disinfection. About half of the cases, in both groups, still harbored detectable amounts of bacteria.

The efficacy of five different techniques in identifying C-shaped canals in mandibular molars.

Information regarding the canal anatomy especially in complex cases such as C-shaped canals is essential for a successful treatment. In this study, five different methods for identification of C-shaped canal configuration were compared. 108 extracted mandibular molars with fused roots were studied. Radiographic evaluation was carried out using periapical radiography and CBCT. After access cavity preparation, all specimens were evaluated by direct visual examination and then under dental operating microscope. Finally, the actual anatomy of each sample was determined by preparing horizontal cross sections of the roots (1mm thick) and examining them under stereomicroscope as the gold standard. Among the techniques used, high-resolution CBCT manifested the highest accuracy, whereas periapical radiography had the lowest. All approaches can be useful in reaching a correct diagnosis. CBCT, especially the low-resolution modality, is an effective technique in the diagnosis of C-shaped anatomy.

Association between the presence of distolingual root in mandibular first molars and the presence of C-shaped mandibular second molars: a CBCT study in a Taiwanese population.

The purpose of this study was to assess the prevalence of C-shaped canals in permanent mandibular second molars (SMs) and to determine whether its appearance was associated with the presence of distolingual root (DLR) in permanent mandibular first molars (FMs). Three hundred and eighty patients were qualified for evaluation of their FMs and SMs using cone beam computed tomography. The prevalence, distribution pattern, external root morphology, and the internal root canal anatomy of the examined molars were recorded and analyzed. Furthermore, the association between the root canal configurations of SMs and the appearance of DLR in FMs was also assessed. The prevalence of SMs with C-shaped root canals was 44.7%. The most common root canal configuration type of the one-rooted SMs with C-shaped anatomy was C3 (45.6%), followed by C2 and C1. The frequency of C-shaped canals in SMs was 45.4% in Non-DLR group, 52.8% in unilateral DLR group, and 33.9% in bilateral DLR group, respectively. Moreover, the prevalence of C-shaped root canals in SMs with the presence of bilateral DLRs in FMs was significantly lowered. The association between the presence of DLR in FMs and C-shaped canal configurations in neighboring SMs was surveyed, and the prevalence of C-shaped root canals in SMs with the presence of bilateral DLRs in FMs was found to be significantly lowered.